Before you say anything to DH, you need to speak to your DSS again and find out if this is something he told you in confidence or not. If it is, then no don't say anything to your DH. If it's not then let him know that you would like to say something to him about it. Maybe you can try to encourage your DSS to tell DH himself.

Everything he told me, was obviously not something he wanted his father to know that he knew. He said something about how he got a scar on his head. DSS has a 3" scar on his head, something obvious w/ short hair. For years, they've been telling their DS that it was the fault of their pooch that DS got knocked over & required stitches. DSS said to me "my mother told me that my dad was being irresponsible, as always, and left me alone, and because he wasn't watching me, I fell in the bathroom"... he went on about how his father was irresponsible w/ money, my DH, causing my DH & his ex to have financial woes. Again, this is something that has nothing to do w/ how DH is as a father. Not only does 1) DH pay CS, never been late, ever... but the child shouldn't know about the whole $ situation. Ex-wife/bio-mom told the child how he ruined her credit. As much as I already knew this (DH told me this a long time ago, they were really young when they married)...it's not something the child should be hearing. KWIM?

That's what I'm trying to articulate. The child is hearing this information, that I know can only come from her. It's not relevant to DH as a parent & it's sad. I feel really bad. I'm glad DSS has opened up to me, but at the same time, I feel guilty that he's telling me this. It's not his fault (he's the child), but it's the ex-wife/bio-mom, that needs to stop "talking" about that stuff to her child. What happened in her marriage has nothing to do w/ things now. That's where I feel like it's putting me in a sticky situation.